<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

    <script>

        var arr1 = ['it','bai'];
        var arr2 = ['zhan','hello'];

        var arr3 = arr1.concat(arr2);
        console.log(arr1) //concat不会改变原数组
        console.log(arr2)
        console.log(arr3)

    </script>

</body>
</html>